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KNOT TYINGMANUAL

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SELECTED TERMS 2

Absorption Rate Measures how quickly a suture is absorbed or broken down by the body. Refers only to the presence or absence ofsuture material and not to the amount of strength remaining in the suture.

Breaking Strength Retention (BSR) Measures tensile strength(see below) retained by suture in vivo over time. For example, a suturewith an initial tensile strength of 20 lbs. and 50% of its BSR at 1 week has 10 lbs. of tensile strength in vivo at 1 week.

Extensibility The characteristic of suture stretch during knot tying and recovery thereafter. Familiarity with suture’s extensibility will help thesurgeon know when the suture knot is snug.

Memory Refers to a suture’s tendency to retain kinks or bends (set bythe material’s extrusion process or packaging) instead of lying flat.

Monofilament Describes a suture made of a single strand or filament.

Multifilament Describes a suture made of several braided or twistedstrands or filaments.

Tensile Strength The measured pounds of tension that a knotted

suture strand can withstand before breaking.

United States Pharmacopeia (USP) An organization that promotes the public health by establishing and disseminating officially recognized standards of quality and authoritative information for the use of medicines and other healthcare technologies by health professionals,patients, and consumers.

The KNOT TYING MANUAL and practice board are available from ETHICON, INC., for all learners of suturing and knot-tying techniques.

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Surgery draws upon all the sciences, but its very natureplaces it in the category of an art. Dexterity and speed intying knots correctly constitute an art which only practicecan make perfect.

Of the more than 1,400 different types of knots described in THE ENCYCLOPEDIA OF KNOTS, only a few are used inmodern surgery. It is of paramount importance that eachknot placed for approximation of tissues or ligation of vessels be perfect. It must hold with proper tension.

In the early days of surgery, materials were heavy and crude,knots bulky and inefficient. It was not unusual for the surgeon to place three or even four knots in the suturestrand “just to be sure” it would hold.

Research and refinements of manufacture and sterilizationhave provided the surgeon of today with a wide choice ofnatural and synthetic suture materials. The successful use ofany of these is dependent upon skillful knot tying andmeticulous care in the handling of the suture.The adoptionof finer gauge sutures has been accompanied by morerefined, simplified and standardized suturing techniques.

It is the hope of ETHICON, INC., that this KNOT TYINGMANUAL will help train medical students, surgical residents,physician assistants and others in the techniques of knottying and the handling of sutures.

ETHICON, INC.† Contributing Designer—Bashir Zikria, MD, FACS

FOREWORD (PRACTICE BOARD†)

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Basic Knots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Knot Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

General Principles of Knot Tying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Square Knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Two-Hand Technique. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

One-Hand Technique. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Surgeon’s or Friction Knot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Deep Tie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Ligation Around Hemostatic Clamp . . . . . . . . . . . . . . . . . . . . . . . . 27

More Common of Two Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Alternate Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Instrument Tie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Granny Knot. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Suture Materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Principles of Suture Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Surgical Needles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

TABLE OF CONTENTS 4

1. Simple knot: incomplete basic unit2. Square knot: completed common knot3. Surgeon’s or Friction knot: completed tension knot

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*Trademark

BASIC KNOTS

The knots demonstrated on the following pages are thosemost frequently used, and are applicable to all types of operative procedures.The camera was placed behind thedemonstrator so that each step of the knot is shown as seenby the operator. For clarity, one half of the strand is purpleand the other white. The purple working strand is initially held in the right hand. The left-handed person may choose to study the photographs in a mirror.

KNOT SECURITYThe construction of ETHICON* sutures has been carefullydesigned to produce the optimum combination of strength,uniformity, and hand for each material. The term hand isthe most subtle of all suture quality aspects. It relates to the feel of the suture in the surgeon’s hands, the smoothnesswith which it passes through tissue and ties down, the way

in which knots can be set and snugged down, and most ofall, to the firmness of body of the suture. Extensibility relates to the way in which the suture will stretch slightly duringknot tying and then recover.The stretching characteristicsprovide the signal that alerts the surgeon to the precisemoment when the suture knot is snug.

Multifilament sutures are generally easier to handle and to tie than monofilament sutures; however, all the syntheticmaterials require a specific knotting technique. With multifilament sutures, the nature of the material and thebraided or twisted construction provide a high coefficient of friction and the knots remain as they are laid down. Inmonofilament sutures, on the other hand, the coefficient offriction is relatively low, resulting in greater tendency for the knot to loosen after it has been tied. In addition,monofilament synthetic polymeric materials possess theproperty of memory. Memory is the tendency not to lie flat,but to return to given shape set by the material’s extrusionprocess or the suture’s packaging.The RELAY* suture deliverysystem delivers sutures with minimal package memory dueto its unique package design.

Suture knots must be properly placed to be secure. Speed in tying knots may result in less than perfect placement ofthe strands. In addition to variables inherent in the suturematerials, considerable variation can be found between knotstied by different surgeons and even between knots tied bythe same individual on different occasions.

GENERAL PRINCIPLES OF KNOT TYINGCertain general principles govern the tying of all knots and apply to all suture materials.

1. The completed knot must be firm, and so tied that slipping is virtually impossible. The simplest knot for the material is the most desirable.

2. The knot must be as small as possible to prevent anexcessive amount of tissue reaction when absorbablesutures are used, or to minimize foreign body reaction to nonabsorbable sutures. Ends should be cut as short as possible.

3. In tying any knot, friction between strands (“sawing”)must be avoided as this can weaken the integrity of the suture.

4. Care should be taken to avoid damage to the suturematerial when handling. Avoid the crushing or crimpingapplication of surgical instruments, such as needleholdersand forceps, to the strand except when grasping the freeend of the suture during an instrument tie.

5. Excessive tension applied by the surgeon will causebreaking of the suture and may cut tissue. Practice inavoiding excessive tension leads to successful use offiner gauge materials.

6. Sutures used for approximation should not be tied too tightly, because this may contribute to tissue strangulation.

7. After the first loop is tied, it is necessary to maintain traction on one end of the strand to avoid loosening of the throw if being tied under any tension.

8. Final tension on final throw should be as nearly horizontal as possible.

9. The surgeon should not hesitate to change stance orposition in relation to the patient in order to place a knot securely and flat.

10. Extra ties do not add to the strength of a properly tied knot. They only contribute to its bulk. With somesynthetic materials, knot security requires the standardsurgical technique of flat and square ties with additionalthrows if indicated by surgical circumstance and theexperience of the surgeon.

An important part of good suturing technique is correctmethod in knot tying. A seesaw motion, or the sawing ofone strand down over another until the knot is formed,may materially weaken sutures to the point that they maybreak when the second throw is made or, even worse, in the postoperative period when the suture is furtherweakened by increased tension or motion.

If the two ends of the suture are pulled in opposite directions with uniform rate and tension, the knot may betied more securely. This point is well illustrated in the knottying techniques shown in the next section of this manual.

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The two-hand square knot is the easiest andmost reliable for tying most suture materials.

1 2White strand placed over extended index finger of left hand acting as bridge, and heldin palm of left hand. Purple strand held inright hand.

Purple strand held in right hand broughtbetween left thumb and index finger.

SQUARE KNOT TWO-HAND TECHNIQUE

1

Left hand turned inward by pronation, and thumb swung under white strand toform first loop.

Purple strand crossed over white and heldbetween thumb and index finger of left hand.3 4

STEPS 1-4

Standard technique of flat and square ties with additional

throws if indicated by the surgical circumstance and the

experience of the operator should be used to tie Coated VICRYL*

Plus Antibacterial (polyglactin 910) suture, Coated VICRYL*

(polyglactin 910) suture, MONOCRYL* (poliglecaprone 25)

suture, Coated VICRYL RAPIDE * (polyglactin 910) suture,

PDS* II (polydioxanone) suture, ETHILON* nylon suture,

ETHIBOND* EXCEL polyester suture, PERMA-HAND* silk suture,

PRONOVA* poly (hexafluoropropylene-VDF) suture,

and PROLENE* polypropylene suture.

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5 6Right hand releases purple strand. Then lefthand supinated, with thumb and index fingerstill grasping purple strand, to bring purplestrand through the white loop. Regrasp purple strand with right hand.

Purple strand released by left hand andgrasped by right. Horizontal tension isapplied with left hand toward and right hand away from operator. This completes first half hitch.

SQUARE KNOT TWO-HAND TECHNIQUE

1

Left index finger released from white strandand left hand again supinated to loop whitestrand over left thumb.

Purple strand held in right hand is angledslightly to the left. Purple strand broughttoward the operator with the right hand andplaced between left thumb and index finger.Purple strand crosses over white strand.

7 8

STEPS 5-8 10

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9 10By further supinating left hand, white strandslides onto left index finger to form a loop aspurple strand is grasped between left indexfinger and thumb.

Left hand rotated inward by pronationwith thumb carrying purple strandthrough loop of white strand. Purplestrand is grasped between right thumband index finger.

SQUARE KNOT TWO-HAND TECHNIQUE

1

Horizontal tension applied with lefthand away from and right hand towardthe operator. This completes the secondhalf hitch.

The final tension on the final throwshould be as nearly horizontal as possible.11 12

STEPS 9-12 12

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Wherever possible, the square knot is tied usingthe two-hand technique. On some occasions itwill be necessary to use one hand, either theleft or the right, to tie a square knot.Theseillustrations employ the left-handed technique.

1 2White strand held between thumb and indexfinger of left hand with loop over extendedindex finger. Purple strand held betweenthumb and index finger of right hand.

Purple strand brought over white strand onleft index finger by moving right hand awayfrom operator.

SQUARE KNOT ONE-HAND TECHNIQUE

1

With purple strand supported in right hand,the distal phalanx of left index finger passesunder the white strand to place it over tip of left index finger. Then the white strand is pulled through loop in preparation forapplying tension.

The first half hitch is completed by advancingtension in the horizontal plane with the lefthand drawn toward and right hand awayfrom the operator.

3 4

STEPS 1-4

The sequence of throws illustrated is most commonly used

for tying single suture strands. The sequence may be

reversed should the surgeon be holding a reel of suture

material in the right hand and placing a series of ligatures.

In either case, it cannot be too strongly emphasized that

the directions the hands travel must be reversed proceeding

from one throw to the next to ensure that the knot formed

lands flat and square. Half hitches result if this precaution is

not taken.

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5 6White strand looped around three fingers ofleft hand with distal end held between thumband index finger.

Purple strand held in right hand broughttoward the operator to cross over the whitestrand. Continue hand motion by flexing distal phalanx of left middle finger to bring it beneath white strand.

SQUARE KNOT ONE-HAND TECHNIQUE

1

As the middle finger is extended and the lefthand pronated, the white strand is broughtbeneath the purple strand.

Horizontal tension applied with the left handaway from and the right hand toward theoperator. This completes the second halfhitch of the square knot. Final tension shouldbe as nearly horizontal as possible.

7 8

STEPS 5-8 16

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1 2White strand placed over extended index finger of left hand and held in palm of lefthand. Purple strand held between thumb andindex finger of right hand.

Purple strand crossed over white strand bymoving right hand away from operator at anangle to the left. Thumb and index finger ofleft hand pinched to form loop in the whitestrand over index finger.

SURGEON’S OR FRICTION KNOT

1

Left hand turned inward by pronation, andloop of white strand slipped onto left thumb.Purple strand grasped between thumb andindex finger of left hand. Release right hand.

Left hand rotated by supination extendingleft index finger to pass purple strandthrough loop. Regrasp purple strand withright hand.

3 4

STEPS 1-4

The surgeon’s or friction knot is recommended for tying

Coated VICRYL* Plus Antibacterial (polyglactin 910) suture,

Coated VICRYL* (polyglactin 910) suture, ETHIBOND*

EXCEL polyester suture, ETHILON* nylon suture,

MERSILENE* polyester fiber suture, NUROLON* nylon

suture, PRONOVA* poly (hexafluoropropylene-VDF) suture,

and PROLENE* polypropylene suture.

The surgeon’s knot also may be performed using a one-hand

technique in a manner analogous to that illustrated for the

square knot one-hand technique.

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5 6The loop is slid onto the thumb of the lefthand by pronating the pinched thumb andindex finger of left hand beneath the loop.

Purple strand drawn left with right hand and again grasped between thumb and indexfinger of left hand.

SURGEON’S OR FRICTION KNOT

1

Left hand rotated by supination extendingleft index finger to again pass purple strandthrough, forming a double loop.

Horizontal tension is applied with left handtoward and right hand away from the operator. This double loop must be placed inprecise position for the final knot.

7 8

STEPS 5-8 20

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9 10With thumb swung under white strand, purple strand is grasped between thumb and index finger of left hand and held overwhite strand with right hand.

Purple strand released. Left handsupinates to regrasp purple strand withindex finger beneath the loop of thewhite strand.

SURGEON’S OR FRICTION KNOT

1

Purple strand rotated beneath the whitestrand by supinating pinched thumband index finger of left hand to drawpurple strand through the loop. Right hand regrasps purple strand tocomplete the second throw square.

Hands continue to apply horizontal tension with left hand away from andright hand toward the operator. Finaltension on final throw should be asnearly horizontal as possible.

11 12

STEPS 9-12 22

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Tying deep in a body cavity can be difficult.The square knot must be firmly snugged downas in all situations.

However, the operator must avoid upward tension which may tear or avulse the tissue.

1 2Strand looped around hook in plastic cup onPractice Board with index finger of righthand which holds purple strand in palm ofhand. White strand held in left hand.

Purple strand held in right hand broughtbetween left thumb and index finger. Lefthand turned inward by pronation, and thumb swung under white strand to form the first loop.

DEEP TIE

1

By placing index finger of left hand on whitestrand, advance the loop into the cavity.

Horizontal tension applied by pushing downon white strand with left index finger whilemaintaining countertension with index fingerof right hand on purple strand.

3 4

STEPS 1-4 24

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5 6Purple strand looped over and under whitestrand with right hand.

Purple strand looped around white strand toform second loop. This throw is advancedinto the depths of the cavity.

DEEP TIE

1

Horizontal tension applied by pushing downon purple strand with right index finger whilemaintaining countertension on white strandwith left index finger. Final tension should beas nearly horizontal as possible.

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STEPS 5-7 26

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Frequently it is necessary to ligate a blood vessel or tissue grasped in a hemostatic clampto achieve hemostasis in the operative field.

1 2When sufficient tissue has been cleared awayto permit easy passage of the suture ligature,the white strand held in the right hand ispassed behind the clamp.

Left hand grasps free end of the strand andgently advances it behind clamp until bothends are of equal length.

LIGATION AROUND HEMOSTATIC CLAMP

1

To prepare for placing the knot square, thewhite strand is transferred to the right handand the purple strand to the left hand, thuscrossing the white strand over the purple.

As the first throw of the knot is completed, theassistant removes the clamp. This maneuverpermits any tissue that may have beenbunched in the clamp to be securely crushed bythe first throw. The second throw of the squareknot is then completed with either a two-handor one-hand technique as previously illustrated.

3 4

MORE COMMON OF TWO METHODS STEPS 1-4 28

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Some surgeons prefer this technique becausethe operator never loses contact with the sutureligature as in the preceding technique.

1 2Center of the strand placed in front of the tipof hemostatic clamp with purple strand heldin right hand and white strand in left hand.

Purple strand swung behind clamp andgrasped with index finger of left hand. Purplestrand will be transferred to left hand andreleased by right.

LIGATION AROUND HEMOSTATIC CLAMP

1

Purple strand crossed under white strandwith left index finger and regrasped withright hand.

First throw is completed in usual manner.Tension is placed on both strands below thetip of the clamp as the first throw of the knotis tied. The assistant then removes theclamp. The square knot is completed witheither a two-hand or one-hand technique aspreviously illustrated.

3 4

ALTERNATE TECHNIQUE STEPS 1-4 30

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The instrument tie is useful when one or bothends of the suture material are short. For bestresults, exercise caution when using a needle-holder with any monofilament suture, as repeatedbending may cause these sutures to break.

1 2Short purple strand lies freely. Long whiteend of strand held between thumb and indexfinger of left hand. Loop formed by placingneedleholder on side of strand away fromthe operator.

Needleholder in right hand grasps short purple end of strand.

INSTRUMENT TIE

1

First half hitch completed by pulling needleholder toward operator with righthand and drawing white strand away from operator. Needleholder is released from purple strand.

First half hitch completed by pulling needleholder toward operator with righthand and drawing white strand away fromoperator. Needleholder is released from purple strand.

3 4

STEPS 1-4 32

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5 6With end of the strand grasped by theneedleholder, purple strand is drawn through loop in the white strand away from the operator.

Square knot completed by horizontal tensionapplied with left hand holding white strandtoward operator and purple strand in needle-holder away from operator. Final tensionshould be as nearly horizontal as possible.

INSTRUMENT TIE STEPS 5-6

1GRANNY KNOT

A granny knot is not recommended. However, itmay be inadvertently tied by incorrectly crossingthe strands of a square knot. It is shown only towarn against its use. It has the tendency to slipwhen subjected to increasing pressure.

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�SUTURE MATERIAL

The requirement for wound support varies in different tissues from a few days for muscle, subcutaneous tissue, andskin; weeks or months for fascia and tendon; to long-termstability, as for vascular prosthesis. The surgeon must beaware of these differences in the healing rates of various tissues and organs. In addition, factors present in the individual patient, such as infection, debility, respiratoryproblems, obesity, etc, can influence the postoperativecourse and the rate of healing.

Suture selection should be based on the knowledge of thephysical and biologic characteristics of the material in relationship to the healing process. The surgeon wants to ensure that a suture will retain its strength until the tissue regains enough strength to keep the wound edgestogether on its own. In some tissue that might never regain preoperative strength, the surgeon will want suture materialthat retains strength for a long time. If a suture is going to be placed in tissue that heals rapidly, the surgeon mayprefer to select a suture that will lose its tensile strength at about the same rate as the tissue gains strength and thatwill be absorbed by the tissue so that no foreign materialremains in the wound once the tissue has healed. With allsutures, acceptable surgical practice must be followed withrespect to drainage and closure of infected wounds.Theamount of tissue reaction caused by the suture encourages or retards the healing process.

When all these factors are taken into account, the surgeonhas several choices of suture materials available. Selection canthen be made on the basis of familiarity with the material,its ease of handling, and other subjective preferences.

Sutures can conveniently be divided into two broad groups:absorbable and nonabsorbable. Regardless of its composition,suture material is a foreign body to the human tissues in whichit is implanted and to a greater or lesser degree will elicit aforeign body reaction.

Two major mechanisms of absorption result in the degradation of absorbable sutures. Sutures of biological origin such as surgical gut are gradually digested by tissueenzymes. Sutures manufactured from synthetic polymers are principally broken down by hydrolysis in tissue fluids.

Nonabsorbable sutures made from a variety of nonbiodegradable materials are ultimately encapsulated or walled off by the body’s fibroblasts. Nonabsorbablesutures ordinarily remain where they are buried within the tissues. When used for skin closure, they must beremoved postoperatively.

1

A further subdivision of suture materials is useful:monofilament and multifilament. A monofilament suture ismade of a single strand. It resists harboring microorganisms,and it ties down smoothly. A multifilament suture consists ofseveral filaments twisted or braided together.This gives goodhandling and tying qualities. However, variability in knotstrength among multifilament sutures might arise from thetechnical aspects of the braiding or twisting process.

The sizes and tensile strengths for all suture materials arestandardized by USP regulations. Size denotes the diameterof the material. Stated numerically, the more zeroes (0’s) in the number, the smaller the size of the strand. As thenumber of 0’s decreases, the size of the strand increases.The 0’s are designated as 5-0, for example, meaning 00000which is smaller than a size 4-0.The smaller the size, theless tensile strength the strand will have.Tensile strength of a suture is the measured pounds of tension that the strandwill withstand before it breaks when knotted.

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�PRINCIPLES OF SUTURE SELECTION

The surgeon has a choice of suture materials from which to select for use in body tissues. Adequate strength of thesuture material will prevent suture breakage. Secure knotswill prevent knot slippage. But the surgeon must understandthe nature of the suture material, the biologic forces in thehealing wound, and the interaction of the suture and the tissues.The following principles should guide the surgeon in suture selection.

1.WHEN A WOUND HAS REACHED MAXIMALSTRENGTH, SUTURES ARE NO LONGER NEEDED.THEREFORE:

a.Tissues that ordinarily heal slowly, such as fascia andtendons, should usually be closed with nonabsorbablesutures. An absorbable suture with extended (up to 6months) wound support may also be used.

b.Tissues that heal rapidly, such as stomach, colon, andbladder, may be closed with absorbable sutures.

2. FOREIGN BODIES IN POTENTIALLY CONTAMINATEDTISSUES MAY CONVERT CONTAMINATION TOINFECTION.THEREFORE:

a. Avoid multifilament sutures which may convert a contaminated wound into an infected one.

b. Use monofilament or absorbable sutures in potentiallycontaminated tissues.

3.WHERE COSMETIC RESULTS ARE IMPORTANT,CLOSE AND PROLONGED APPOSITION OF WOUNDSAND AVOIDANCE OF IRRITANTS WILL PRODUCE THEBEST RESULT.THEREFORE:

a. Use the smallest inert monofilament suture materialssuch as nylon or polypropylene.

b. Avoid skin sutures and close subcuticularly,whenever possible.

c. Under certain circumstances, to secure close appositionof skin edges, a topical skin adhesive such as DERMABOND* Topical Skin Adhesive, or skin closuretape such as PROXI-STRIP* Skin Closures, may be used.

4. FOREIGN BODIES IN THE PRESENCE OF FLUIDS CONTAINING HIGH CONCENTRATIONS OF CRYSTALLOIDS MAY ACT AS A NIDUS FOR PRECIPITATION AND STONE FORMATION.THEREFORE:

a. In the urinary and biliary tract, use rapidly absorbedsutures.

5. REGARDING SUTURE SIZE:

a. Use the finest size, commensurate with the naturalstrength of the tissue.

b. If the postoperative course of the patient may producesudden strains on the suture line, reinforce it withretention sutures. Remove them as soon as the patient’scondition is stabilized.

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METRIC MEASURES AND USP SUTURE DIAMETER EQUIVALENTS

USP Size 11-0 10-0 9-0 8-0 7-0 6-0 5-0 4-0 3-0 2-0 0 1 2 3 4 5 6

Natural Collagen – 0.2 0.3 0.5 0.7 1.0 1.5 2.0 3.0 3.5 4.0 5.0 6.0 7.0 8.0 – –

Synthetic Absorbables – 0.2 0.3 0.4 0.5 0.7 1.0 1.5 2.0 3.0 3.5 4.0 5.0 6.0 6.0 7.0 –

Nonabsorbable Materials 0.1 0.2 0.3 0.4 0.5 0.7 1.0 1.5 2.0 3.0 3.5 4.0 5.0 6.0 6.0 7.0 8.0

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�SURGICAL NEEDLES

Necessary for the placement of sutures in tissue, surgical needles must be designed to carry suture material through tissue with minimal trauma.They must be sharp enough topenetrate tissue with minimal resistance.They should be rigidenough to resist bending, yet flexible enough to bend beforebreaking.They must be sterile and corrosion-resistant to prevent introduction of microorganisms or foreign bodiesinto the wound.

To meet these requirements, the best surgical needles aremade of high quality stainless steel, a noncorrosive material.Surgical needles made of carbon steel may corrode, leavingpits that can harbor microorganisms. All ETHICON* stainlesssteel needles are heat-treated to give them the maximum possible strength and ductility to perform satisfactorily in the body tissues for which they are designed. ETHALLOY*

needle alloy, a noncorrosive material, was developed forunsurpassed strength and ductility in precision needles used in cardiovascular, ophthalmic, plastic, and microsurgical procedures.

Ductility is the ability of the needle to bend to a given angleunder a given amount of pressure, called load, without breaking. If too great a force is applied to a needle it maybreak, but a ductile needle will bend before breaking. If a surgeon feels a needle bending, this is a signal that excessiveforce is being applied.The strength of a needle is determined inthe laboratory by bending the needle 90˚; the required force isa measurement of the strength of the needle. If a needle is weak, it will bend too easily and can compromise the surgeon’s control and damage surrounding tissue duringthe procedure.

Regardless of ultimate intended use, all surgical needles have three basic components: the attachment end, the body,and the point.

The majority of sutures used today have appropriate needlesattached by the manufacturer. Swaged sutures join the needleand suture together as a continuous unit that is convenient touse and minimizes tissue trauma. ATRALOC* surgical needles,which are permanently swaged to the suture strand, are supplied in a variety of sizes, shapes, and strengths. Someincorporate the CONTROL RELEASE* needle suture principlewhich facilitates fast separation of the needle from the suturewhen desired by the surgeon. Even though the suture issecurely fastened to the needle, a slight, straight tug on theneedleholder will release it.This feature allows rapid placementof many sutures, as in interrupted suture techniques.

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The body, or shaft, of a needle is the portion which is grasped by theneedleholder during the surgical procedure.The body should be as close as possible to the diameter of the suture material.Thecurvature of the body may be straight, half-curved, curved, or compound-curved.The cross-sectional configuration of the bodymay be round, oval, side-flattened rectangular, triangular, or trapezoidal.The oval, side-flattened rectangular, and triangularshapes may be fabricated with longitudinal ribs on the inside or outside surfaces.This feature provides greater stability of the needle in the needleholder.

The point extends from the extreme tip of the needle to the maximum cross-section of the body.The basic needle points arecutting, tapered, or blunt. Each needle point is designed and produced to the required degree of sharpness to smoothly penetrate the types of tissue to be sutured.

Surgical needles vary in size and wire gauge.The diameter is thegauge or thickness of the needle wire.This varies from 30 microns(.001 inch) to 56 mil (.045 inch, 1.4 mm).Very small needles of fine gauge wire are needed for microsurgery. Large, heavy gaugeneedles are used to penetrate the sternum and to place retentionsutures in the abdominal wall. A broad spectrum of sizes are available between these two extremes.

Of the many types available, the specific needle selected for use isdetermined by the type of tissue to be sutured, the location andaccessibility, size of the suture material, and the surgeon’s preference.

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�TRADEMARKS

THE FOLLOWING ARE TRADEMARKS OFETHICON, INC.:

ATRALOC surgical needle

Coated VICRYL (polyglactin 910) suture

Coated VICRYL Plus Antibacterial (polyglactin 910) suture

Coated VICRYL RAPIDE (polyglactin 910) suture

CONTROL RELEASE needle/needle suture

CS ULTIMA ophthalmic needle

ETHALLOY needle alloy

ETHIBOND EXCEL polyester suture

ETHICON sutures or products

ETHILON nylon suture

LIGAPAK dispensing reel

MERSILENE polyester fiber suture

MICRO-POINT surgical needle

MONOCRYL (poliglecaprone 25) suture

NUROLON nylon suture

P PRIME needle

PC PRIME needle

PS PRIME needle

PDS II (polydioxanone) suture

PERMA-HAND silk suture

PROLENE polypropylene suture

PRONOVA poly (hexafluoropropylene-VDF) suture

RELAY suture delivery system

SABRELOC spatula needle

TAPERCUT surgical needle

VICRYL (polyglactin 910) suture

VISI-BLACK surgical needle

1NOTES 42

1-800-4ETHICON

W W W. E T H I C O N . C O M

ETHICON, INC., PO BOX 151, SOMERVILLE, NJ 08876-0151

* TRADEMARK

©2005, ETHICON, INC.

KTMOOR